Motor-control system.



No. 729,117. PATBNTED MAY 26', 1903. 0.. BKBARRY. MOTOR comnor. SYSTEM.

APPLICATION TILED FEB. 12, 1902.

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UNITED STATES Patented May 26, 1903 PATENT OFFICE.

CHARLES E. BARRY, OF SCHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

MOTOR-CONTROL SYSTEM.

SPECIFICATION forming part of Letters Patent N 0. 729,1 17, dated. May26, 1903. Application filed February 12, 1902. Serial No. 93,711. (Nomodel.)

To all whom, it may concern:

Be it known that I, CHARLES E. BARRY, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Motor-Control Systems,of which the following is a specification.

My invention relates to systems of motorcontrol in which overload andunderload circuit-breaking devices are employed in combination with themotor-controller or rheostat.

The main object of myinvention is to prevent the reapplication ofcurrent to the motor-circuit after the said circuit has been opened bythe circuit-breaking devices until the motor or other apparatus in thecircuit has been protected by sufficient resistance.

My invention consists of the combination, in a motor-circuit, of acontroller, a separate switch which operates to open the circuit eitheron an overload or anunderload, and means, such as an auxiliary switch,for preventing said circuit from being completed until the controllerhas been moved into its off or first operative position.

The invention further consists of means for automatically resetting saidcircuit-opening switch when the controller is turned into its firstoperative position.

One application of the present invention is in the control ofprinting-press motors; but it may be applied in a variety of ways tovarious devices driven by electrical power without departing from thespirit of my invention.

My invention will be better understood by reference to the followingdescription, taken in connection with the accompanying drawings.

In the drawings, Figure 1 is a diagrammatic view of the motor-circuit,including the controller and its connections. Fig. 2 is a side View,partlyin section, of one form of an electromagnetically-controlledcircuit-opening switch which may be used in connection with myinvention.

Referring to Fig. 1, M represents the motor of an electrically-drivendevice, such as a printing-press or the like. The motor M is controlledby the controller R, the arm a of which is actuated by the pilot-motor Mthrough the agency of a worm and gear mounted on the shaftssand s,respectively. The pilot-motor M is controlled by the master switch orcontroller C. A represents a common type of overload-switch whichoperates to open the circuit at a in case ofa sudden rush ofcurrent oran overloading of the motor M. B represents anelectromagnetically-operated circuitopening switch whichwill'automatically open the circuit in which the motor M is located incase of a loss of voltage on the supply-mains and also in case of anopening of the circuit at a by the operation of the overload-switch A.The switch Bis so constructed that so long as the solenoid Hremainsenergized the auxiliary switch-contacts E F and switch member L remainclosed, and immediately upon the failure of the Voltage of the line oran overload the solenoid becomes denergized and the switch-contacts E Fand member L automatically open. When the controllerarm a is movedforward by means of the pilotmotor M, (the connections of which will behereinafter explained,) so that the arm a contacts with the specialcontact 0, a circuit is completed through the solenoidof the overloadswitch A from the positive main 1, through the connections 1, arm a,contact 0, connection 9, solenoid H, connection 12, 8o switch-contacts aand 13, back to negative main 2. This energizes H and closes theswitch-contacts E F and operates the switch member L, completing thecircuit through the motor M as follows: positive main 1, solenoid of theoverload-switch A, 1, arm a, resistances r, 1, motor M, 2", switchmember L, to negative main 2. As the arm a moves farther along to cutout more and more of the resistance r and leaves the contact 0 the gocircuit changes and may be readily traced through the followingconnections: positive main 1, solenoid of the overload-switch A, 1", arma,to contact-strip b,from which two separate circuits lead, one throughthe connection 11, auxiliary switch-contacts E F, 10, solenoid H, 12,switch-contacts a 13, to negative main 2, the other through thecontroller and motor M, as before. Thus it will readily be seen that thesolenoid H remains energized joo for any position of the arm a otherthan the oif position so long as there is a supply of current in themains 1 and 2, and the overload-switch A does not operate to open thecircuit. The pilot-motor M is controlled by the master-switch O andoperates to move the member a of the controller R forward and backwardbetween limits prescribed by the switches D and D, which switches openthe circuit of the motor when the arm at has reached the position inwhich all the resistance r is short-'circuited and when the arm a is inthe off position, respectively. This is accomplished by the projectiona, carried by the shaft 3', to which the arm a is attached, striking thepivoted switches D and D, as clearly shown in Fig. 1. For the forwardmovement of the arm Ct the circuit through the motor M may be traced asfollows: positive main 1, 1, master controller-switch O, 6, limit-switchD, 5, field F, 4, armature of M, 3, master controller-switch O, 2, tonegative main 2. For a reverse movement of the arm a the circuit isreadily seen to be: positive main 1, 1 C, 7, limit-switch D, 8, field F1, armature of M, 3, switch 0, 2, to negative main 2.

The circuit-breaker or switch illustrated in Fig. 2 of the drawings isof well-known construction and forms no part of the present invention.Any other form of switch which would operate automatically to open thecircuit on the failure of voltage in the line would answer my purpose aswell.

Referring now to Fig. 2, G is a framework, supporting between its headsg and g a solenoid-coil H. The upper head 9 carries a core I (shown indotted lines) of magnetic material, extending part way into the coil H.A movable arm K, pivoted at one end to lugs 9 carried by the casing G,is operatively connected to a core J, (shown in dotted lines,) which,together with the coil H, constitutes the means for operating theswitch-contacts V and V. The core J is surrounded by a casing ofnon-magnetic material, and adisk of non-magnetic material is interposedbetween the ends of the cores J and I to prevent sticking. The arm K isprovided with a contactcarrying member L, pivotally mounted on the endof the arm. K opposite its pivotal attachment to the lugs g This memberL has an extension Z, which serves to limit the relative movements ofthe arm K and the member L. Ata point removed from the pivot on whichthe member L is mounted a springs is interposed between the ends of themembers K and L, this spring tending normally to keep the extension Z inengagement with the end of the arm K, but permitting the contact V,mounted on the end of the member L, to make a wiping or slidingengagement with the fixed contact V both when the contacts are broughttogether and when they are being separated. The contact V is mounted ona suitable terminal supported on an insulating-board fastened to oneside of the framework G, and both of the contacts are surrounded by aninsulating-chute N, closed in front by the insulated pole-piece Q of ablow-out magnet.

(Not shown.) A block of wood or other insulating material m, attached tothe arm K, carries a pair of spring contact-arms E,electrically'connected. Rigidly attached to the frame G is a pair ofblocks n of insulating material, each of which carries a contact F, towhich the wires 10 and 11, respectively, Fig. 1, may be attached, asatf. When the solenoid H is energized, the core J, with which the arm Kis operatively connected, is raised and the switch-contacts E and V arebrought into communication with the contacts F and V, respectively.

In order to insulate the base or casting on which the switch ismounted,the holes through which the supporting-bolts are passed areprovided with insulating-bushings 9.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is-- 1. In combination, a motor-circuit, a controller insaid circuit, a separate switch which operates to open said circuiteither on overload or underload, and means for automatically resettingsaid switch when the controller is moved into its first operativeposition.

2. The combination in a motor-circuit, of a controller, a separateswitch for opening said circuit on an underload, a switch separate fromthe first-mentioned switch for causing said first-mentioned switch toopen the said circuit on an overload,and an auxiliary switch forpreventing said circuit from being closed after it has been opened bythe operation of either of said switches until the controller has beenturned to the off or first operative position.

3. In a motor-circuit, a controller, means for operating saidcontroller, a switch separate from said controller for automaticallyopening said circuit when there is a failure of voltage or an excess ofcurrent, and an auxiliary switch operatively connected with said switchfor preventing the completion of said circuit until said controller hasbeen returned to its off or first operative position.

at. In a motor-circuit, a controller, means for operating saidcontroller from a distance, means separate from said controller foropening said circuit either on overload or underload, and means forpreventing the completion of said circuit after it has been opened untilthe said controller has been turned to its off or first operativeposition.

5. In combination, a motor-circuit, a controller in said circuit, anelectromagneticallyactuated switch which operates to open said circuiton overload or underload, and means for maintaining the circuit throughthe actuating-coil of said switch open after the switch has operateduntil the controller is moved into its first operative position.

6. In combination, an electrical circuit, anelectromagnetically-actuated switch operating to open said circuit on anunderload, a switch operating to cause said electromagnetically-actuatedswitch to open said circuit on an overload, a controller, and electricalconnections including an auxiliary switch for preventing said circuitfrom being completed after it has been opened by the operation of eitherof said switches until the controller has been turned into its off orfirst operative position.

7. The combination of a controller, means for operating said controller,an electromagnetically-actuated switch in series with said controller, aswitch adapted to cause the said electromagnetically-actuated switch toopen on an overload, a separate switch adapted to open with saidelectromagnetically-actuated switch on an underload, said separateswitch being so connected as to prevent the closing of saidelectromagnetically-actuated switch until the controller has been turnedto its off or first operative position.

8. The combination of a controller, means for operating said controller,an electromagnetioally-actuated switch in series with said controller,contacts at the first operative position of the controller arranged toclose a aircuit through the actuating-Winding of the saidelectromagnetically-actuated switch,and contacts operatively related tothe switch itself for maintaining said circuit closed after thecontroller has been moved into its succeeding operative positions.

9. The combination of a controller, means for operating said controller,an electromagnetically-actuated switch in series with said controller,contacts at the first operative position of the controller arranged toclose a circuit through the actuating-winding of the saidelectromagneticallyactuated switch, contacts operatively related to theswitch itself for maintaining said circuit closed after the controllerhas been moved into its succeeding operative positions, and anoverloadswitch in the circuit of said actuating-windmg.

In witness whereof I have hereunto set my hand this 10th day ofFebruary, 1902.

CHARLES E. BARRY.

Witnesses: BENJAMIN B. HULL,

MARGARET E. WOOLLEY.

